Falling mass generates disturbances in the gravitational field and hence becomes the source of gravitational waves travelling in space-time [1]}. In the lowest order, the gravitational radiation produced in this way depends on a third time derivative of a mass quadrupole moment \(Q_{\alpha \,\beta }^m\) , and is given by a famous Einstein's quadrupole formula [2]}, [3]}
\(P = \frac{G}{45\, c^5} \sum _{\alpha ,\beta } (\dddot{Q}_{\alpha \,\beta }^m)^2 \,.\) 
